Death toll rises in Bangladesh

VIA ProMED Mail 6 February 2011

The death toll due to encephalitishas climbed to 24 in Bangladesh. Nipah virus has been confirmed as the agent of disease by serologic test, and the cause of 4 more deaths Friday and Saturday in Rangpur and Lalmonirhat. The epidemic is currently confined to two villages, and control measures that include district-wide school closures are working to prevent spread. Latest victims are not constrained to a similar age class, ages 4, 16, and 42, suggesting that the Nipah virus is not a selective killer, and its lethality does not depend on a compromised immune system. Twenty-four new patients suffering encephalitis have been admitted to three regional health complexes and are undergoing treatment, with three in critical care.

The Institute of Epidemiology, Disease Control and Research have warned against consuming raw date juice as the Nipah reservoir also drink from dates at night. Fruit bats of the family Pteropodidae are the natural hosts of Nipah, and they show no signs of disease. The outbreak is thought to have begun with bat-human transmission, but in other regions including Malaysia and Singapore, emergence of Nipah in human populations has occurred via direct contact with ill pigs or contaminated tissue. Previously in Bangladesh, approximately half of reported cases were caused by transmission between humans. The highly variable incubation period (4 to 45 days) is a problem for diagnosis and epidemiological investigation and is matched by an also variable fatality rate that ranges from 40-75%. This figure may be affected by local surveillance and treatment capabilities.

Nina